An aural ventilation tube can take many forms but it is intended to be inserted into the human ear drum for the purpose of ventilating the middle ear cleft. In short, it maintains an airway between the middle ear and the external ear canal. It may be called a `drain`, which is a misnomer; a `vent tube`; a `p.e. (pressure equalization) tube` or a `grommet`.
Aural ventilation tubes/grommets are normally inserted with surgical alligator forceps (see FIG. 1). Especially designed inserters have been used, which transport the ventilation tube/grommet by means of a metal pin (see FIG. 2), having an interference fit with the lumen or bore, i.e. the internal diameter of the tube. Once in situ, the pin is withdrawn from the lumen into a tube, the distal end of which, pressing against the outer flange of the grommet, thereby prevents its dislodgement from the incision in the ear drum, so leaving the ventilation tube/grommet in situ.
The ear drum closes the external ear canal, forming a beveled end to the canal. Existing inserters, which fit the internal diameter of the vent tube, are rarely used because they present the leading or inner flange of the ventilation tube/grommet to the ear drum at the wrong angle, which means that it is difficult or, for some clinicians, impossible to locate the device across the ear drum, owing to the length of the narrow, external ear canal, which severely limits the surgeon's ability to manipulate the grommet into the incision in the ear drum.